[CF Lung Disease - a German S3 Guideline: Pseudomonas aeruginosa]

Cystic Fibrosis (CF) is the most common autosomal recessive genetic multisystemic disease. In Germany, it affects at least 8000 people. The disease is caused by mutations in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene leading to dysfunction of CFTR, a transmembrane chloride channel. This defect causes insufficient hydration of the airway epithelial lining fluid which leads to reduction of the mucociliary clearance.Even if highly effective, CFTR modulator therapy has been available for some years and people with CF are getting much older than before, recurrent and chronic infections of the airways as well as pulmonary exacerbations still occur. In adult CF life, Pseudomonas aeruginosa (PA) is the most relevant pathogen in colonisation and chronic infection of the lung, leading to further loss of lung function. There are many possibilities to treat PA-infection.This is a S3-clinical guideline which implements a definition for chronic PA-infection and demonstrates evidence-based diagnostic methods and medical treatment in order to give guidance for individual treatment options.

Frequent Pet Contact as Risk Factor for Allergic Bronchopulmonary Aspergillosis in Cystic Fibrosis

Aspergillus fumigatus (Af) frequently colonizes the respiratory tract of patients with cystic fibrosis (CF). Af is associated with loss of pulmonary function and allergic bronchopulmonary aspergillosis (ABPA), a hypersensitivity fungal lung disease. Environmental factors have impact on CF patients’ lung function variation. The aim of this nationwide questionnaire survey was to investigate the amount of CF patients with frequent pet contact including pet species and to examine the potential impact of frequent pet contact on the occurrence of Af colonization and ABPA diagnosis in these patients. The survey was carried out in 31 German CF centers in 2018. A total of 1232 who completed the surveys were included, and statistical analysis was performed by chi-squared test. Within the study cohort 49.8% of subjects (n = 614; CF patients < 18years: 49.4%, n = 234; ≥ 18years: 50.1%, n = 380) reported frequent contact to pets, of which 60.7% reported frequent contact to dogs, 42.3% to cats and other animals. Of those with frequent pet contact, 71.8% (n = 441) had contact to one pet or more pets from the same family. Af colonization was not significantly associated with frequent pet contact. ABPA diagnosis was documented in 16.7% (n = 206) of all included CF patients and was significantly associated with frequent pet contact (18.9%, n = 116, p = 0.042), confirming previous single center examinations. Particularly, patients with frequent contact to dogs showed an increased ABPA prevalence of 21.3%. Frequent pet contact might be a risk factor for ABPA. CF patients who are sensitized to Af should be informed about the increased risk to develop an ABPA by frequent pet contact. Patients with recurrent onset of ABPA should be evaluated in terms of frequent pet contact.

Urban Life as Risk Factor for Aspergillosis

Aspergillus fumigatus (Af) frequently colonizes the airways of patients with cystic fibrosis (CF) and can cause severe diseases, such as allergic bronchopulmonary aspergillosis, Af bronchitis or even Af pneumonia. However, risk factors, including environmental factors, for acquiring Af in the respiratory tract of patients with CF are rarely studied and described. The aim of this study was to investigate whether urban or rural life could affect colonization with Af in the respiratory tract of patients with CF. Due to privacy policy, registry data are usually not linked to patients´ home addresses. It is therefore very difficult to analyze the influence of the patient´s residential environment. This prospective questionnaire survey was carried out in 31 German CF centers in 2018. Only completed surveys, including a clearly assigned type of residential area were included. Statistical analysis was performed by chi-squared test and logistic regression models. A total of 1016 questionnaires were analyzed (Patients` age: 23 ± 13; 0–88 years; female gender: n=492; 48%). The majority of patients with CF live in large cities (n =314; 30.9%) or urban districts (n=461; 45.4%). Prevalence of 30.2% was found for Af, within the 12 months of investigation period. Af colonization was significantly associated with urban life (p=0.004). Urban live should be considered as possible new risk factor for colonization with Af in the respiratory tract of patients with CF. These new results may raise the awareness of the influence of environmental factors on patient outcomes and should be included in patient guidance and preventive measures.

[CF Lung Disease - a German S3 Guideline: Module 2: Diagnostics and Treatment in Chronic Infection with Pseudomonas aeruginosa]

Cystic Fibrosis (CF) is the most common autosomal-recessive genetic disease affecting approximately 8000 people in Germany. The disease is caused by mutations in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene leading to dysfunction of CFTR, a transmembrane chloride channel. This defect causes insufficient hydration of the epithelial lining fluid which leads to chronic inflammation of the airways. Recurrent infections of the airways as well as pulmonary exacerbations aggravate chronic inflammation, lead to pulmonary fibrosis and tissue destruction up to global respiratory insufficiency, which is responsible for the mortality in over 90 % of patients. The main aim of pulmonary treatment in CF is to reduce pulmonary inflammation and chronic infection. Pseudomonas aeruginosa (Pa) is the most relevant pathogen in the course of CF lung disease. Colonization and chronic infection are leading to additional loss of pulmonary function. There are many possibilities to treat Pa-infection. This is a S3-clinical guideline which implements a definition for chronic Pa-infection and demonstrates evidence-based diagnostic methods and medical treatment for Pa-infection in order to give guidance for individual treatment options.

[New therapeutic strategies in HIV infection-immune reconstitution and virus suppression]

BACKGROUND

In the last years, highly active antiretroviral therapy has decreased AIDS-associated mortality of patients dramatically. Due to this prolonged lifetime, the emergence of resistance against antiretroviral therapy has increased. Additionally, cross-resistance within the classes of nucleoside reverse transcriptase inhibitors (NRTI), non-nucleoside reverse transcriptase inhibitors (NNRTI), and protease inhibitors (PI) complicates HIV therapy. Development of new classes of therapeutic agents can help avoiding cross-resistance. Fuzeon, the first agent in the new class of fusion inhibitors, should be combined with as many effective antiretroviral agents as possible.

CASE REPORT

The course of a 106-week therapy in a patient infected with a multiresistant virus is described.

CONCLUSION

Fusion inhibitor Fuzeon represents a new option for patients having multiple resistance against HAART.

Cell activation by synthetic lipopeptides of the hepatitis C virus (HCV)--core protein is mediated by toll like receptors (TLRs) 2 and 4

T cell epitopes coupled to a lipid moiety (lipopeptides) may be superior immunostimulants compared to peptide antigens and are currently studied as potential vaccines. The cause of enhanced immunogenicity of lipopeptides is largely unknown but members of the novel family of Toll like receptors (TLR) such as TLR2 and TLR4 have been shown to mediate activation of cells in response to bacterial lipopolysaccharide (LPS) and other lipidated bacterial or viral components. We studied TLR-mediated activation by 14 synthetic lipopeptides corresponding to T cell epitopes on hepatitis C virus (HCV) core in human embryonic kidney cells (HEK293) transiently over-expressing TLR2 and in Ba/F3 mouse bone marrow cells stably transfected with TLR4 and the adaptor molecule MD-2. Stimulation of transfected HEK293 or Ba/F3 cells was measured via luciferase activity as a reporter of nuclear factor kappaB activation. Free peptides, a non-HCV-related lipopeptide as well as LPS and the lipopeptide SK4 were used as controls. Ten of the 14 HCV core lipopeptides stimulated luciferase activity in TLR2-transfected HEK293 cells but not in mock-transfected control cells. Nine of the 14 lipopeptides also stimulated luciferase activity in the TLR4/MD-2 double-transfected Ba/F3 cells but not Ba/F3 control cells. Overall, there was a close statistical correlation between TLR2 and TLR4/MD-2-mediated cell activation by the lipopeptides. In contrast, the corresponding free peptides had no stimulatory effect on TLR2 nor on TLR4/MD-2 transfected cells. Thus, lipopeptides but not their corresponding free peptides can activate cells via TLRs 2 and 4. This activation is apparently affected by the amino acid sequence of the peptide moiety.

Transient loss of T-cell reactivity in a patient with hepatitis C virus reinfection

BACKGROUND/AIMS

Self-limited acute hepatitis C virus (HCV) infection with spontaneous recovery is only rarely observed in clinical practice. All existing studies correlate strong cellular immune responses to the recovery from HCV infection.

CASE REPORT

Here, we present a 49-year-old haemophiliac, who had successfully recovered from an acute hepatitis, which was classified retrospectively as HCV infection based on his antibody profiles. This patient was reinfected with HCV 18 years later from an exogenous source, and successfully recovered from this reinfection within 2 months. After his first hepatitis the patient displayed strong cellular responses against recombinant HCV proteins. During reinfection, T-cell proliferation was markedly reduced, while HCV antibody titres increased. However, E2 antibodies were consistently not detectable. T-cell proliferation returned to the pre-reinfection level only several months after loss of viraemia.

DISCUSSION

Our observations resulted in the unexpected finding that our patient cleared HCV reinfection despite an apparent loss of his pre-existing T-cell reactivity in the peripheral blood.

Natural cytotoxicity and antibody-dependent cellular cytotoxicity (ADCC) is not impaired in patients suffering from chronic hepatitis C

BACKGROUND/AIMS

Recent observations suggest that natural killer (NK) cell activity might be impaired in chronic hepatitis C. However, to date antibody-dependent cellular cytotoxicity (ADCC) has not been studied in chronic hepatitis C in detail.

METHODS

Therefore, we investigated spontaneous and cytokine-induced (interleukin-2 and interferon-gamma) natural cytotoxicity and ADCC in 29 patients suffering from chronic hepatitis C and 19 healthy controls. Cytotoxicity was determined with a flow-cytometric assay, which can also assess monocyte cytotoxicity. As target cells we used the colorectal tumor cell line HT29 and the lymphoma cell line Raji.

RESULTS

We found no significant differences with respect to spontaneous cytotoxicity (HCV versus healthy controls (32 vs. 46%) and 17-1A specific ADCC (59 vs. 48%), even if isolated monocytes or NK cells were studied. Preincubation and stimulation of effector cells with cytokines increased both natural cytotoxicity and ADCC by 20-30%. However, natural cytotoxicity and ADCC after stimulation did not differ between the two groups.

CONCLUSIONS

Our data obtained with a long-term cytotoxicity assay do not reveal impaired cytolytic capacity of the innate immune system in chronic hepatitis C, even when isolated monocytes and NK cells were studied as effector cells.